New Target Identified to Boost Immune Cell Cancer-Fighting Ability by Inhibiting Molecular 'Brake'

Researchers at the Van Andel Research Institute have uncovered a promising new approach to enhance the immune system's ability to combat cancer. The study focuses on a molecule called PTGIR, which functions as an immune checkpoint — a regulatory protein that controls T cell activity. When PTGIR levels are high, it acts like a brake, suppressing T cell functions and limiting their capacity to produce molecules that kill cancer cells. This discovery is significant because prostacyclin, a compound present in tumors, interacts with PTGIR and exacerbates T cell exhaustion, making immune responses less effective.

The regulation of PTGIR by the NRF2 protein influences T cell behavior in the tumor environment. Elevated NRF2 activity leads to increased PTGIR expression, further impairing immune cells’ ability to fight cancer. By blocking the PTGIR pathway, scientists hope to reinvigorate exhausted T cells, improving the effectiveness of immunotherapies.

This research opens new avenues for developing targeted cancer treatments. Existing immune checkpoint inhibitors have revolutionized cancer therapy, but not all patients respond to them. Targeting PTGIR could provide an additional strategy for boosting immune responses, especially in cases where current therapies are ineffective. The study, published in Nature Immunology, emphasizes that disrupting the PTGIR-prostacyclin interaction may help lift the immune system's 'brakes,' allowing T cells to more effectively attack tumors.

The findings offer hope for expanding immunotherapy options, with potential for creating novel drugs that modulate this newly identified checkpoint. As immunotherapy continues to evolve, such discoveries are vital for tailored treatments that improve outcomes for a broader range of cancer patients.

source: https://medicalxpress.com/news/2025-06-molecular-immune-cells-cancer.html